Q.

Description:
Task
You are given two numbers a and b where 0 ≤ a ≤ b. Imagine you construct an array of all the integers from a to b inclusive. You need to count the number of 1s in the binary representations of all the numbers in the array.

Example
For a = 2 and b = 7, the output should be 11

Given a = 2 and b = 7 the array is: [2, 3, 4, 5, 6, 7]. Converting the numbers to binary, we get [10, 11, 100, 101, 110, 111], which contains 1 + 2 + 1 + 2 + 2 + 3 = 11 1s.

Input/Output
[input] integer a
Constraints: 0 ≤ a ≤ b.

[input] integer b
Constraints: a ≤ b ≤ 100.

[output] an integer

A)

function rangeBitCount(a, b) {
  //coding and coding..
  let res = 0;
  for (i=a;i<=b;i++) {
    if ( i === 0){
      continue
    }
    res += i.toString(2).match(/1/gi).length
  }
  return res
}